NORTHAMPTON — A Chesterfield man was injured Saturday night after he chased a man who police said stole money from a group of Girl Scouts selling cookies in the lobby of the Wal-Mart store on North King Street.

The injured man, whom police declined to name, is the father of one of the Girl Scouts and got his hand stuck in the window of a vehicle in which the thief fled. The man who pursued the thief was dragged across the parking lot before his hand came free. He fell to the ground, injuring his hands, face and arms, and was treated at Cooley Dickinson Hospital and released, according to police.

The thief got away with an undisclosed amount of cash. Police are investigating.

“The girls are very shaken up,” Pattie Hallberg, chief executive officer of the Girl Scouts of Central and Western Massachusetts, said Sunday. “A very frightening situation both for the adults and the girls.”

Hallberg said the robbery occurred on the first weekend of the Girls Scouts’ annual cookie drive.

The incident unfolded shortly before 8 p.m. when a man approached four Girl Scouts, ages 11 and 12, at a folding table where they were selling cookies. The man, believed to be in his 20s, struck up a conversation with one of the girls, then reached over the table and grabbed a metal money box containing cash and fled, according to police.

One of two adults supervising the Girl Scouts pursued the man into the parking lot, where he got into a vehicle with a driver who had parked in front of the store. Police said none of the Girl Scouts was injured.

“We can deal with the money later,” Hallberg said. “We are making sure they (the Girl Scouts) have the support they need.”

Hallberg said the organization has received an outpouring of support from fellow Girl Scouts and others since the incident occurred. “It’s not something you would expect people to do to the Girl Scouts,” she said.